We aimed to investigate the effect of rest interval, between successive contractions, on muscular fatigue. Methods Eighteen subjects performed elbow flexion and extension (30 repetitions) on an isokinetic dynamometer with 80º of range of motion. The flexion velocity was 120º/s, while for elbow extension we used 5 different velocities (30, 75, 120, 240, 360º/s), producing 5 different rest intervals (2.89, 1.28, 0.85, 0.57 and 0.54 s). Results We observed that when the rest interval was 2.89 s there was a reduction in fatigue. On the other hand, when the rest interval was 0.54 s the fatigue was increased. Conclusions When the resting time was lower (0.54 s) the decline of work in the flexor muscle group was higher compared with different rest interval duration.
R E S E A R C HOpen Access Effect of the rest interval duration between contractions on muscle fatigue 1,5 22 2,42 Daniel V Nogueira, Sidney B Silva , Luiz Carlos de Abreu , Vitor E Valenti, Mahmi Fujimori , 2,3 11 1 Carlos Bandeira de Mello Monteiro, Charli Tortoza , Wellington Ribeiro , Rodrigo A LazoOsório 5* and Carlos J TierraCriollo
* Correspondence: tccarlosj@gmail. com 5 Programa de Engenharia Biomédica COPPE, Universidade Federal do Rio de Janeiro (UFRJ), Av. Pedro Calmon, 550 Prédio da Reitoria, 2° andar, Rio de Janeiro, RJ 21941901, Brazil Full list of author information is available at the end of the article
Abstract Background:We aimed to investigate the effect of rest interval, between successive contractions, on muscular fatigue. Methods:Eighteen subjects performed elbow flexion and extension (30 repetitions) on an isokinetic dynamometer with 80º of range of motion. The flexion velocity was 120º/s, while for elbow extension we used 5 different velocities (30, 75, 120, 240, 360º/s), producing 5 different rest intervals (2.89, 1.28, 0.85, 0.57 and 0.54 s). Results:We observed that when the rest interval was 2.89 s there was a reduction in fatigue. On the other hand, when the rest interval was 0.54 s the fatigue was increased. Conclusions:When the resting time was lower (0.54 s) the decline of work in the flexor muscle group was higher compared with different rest interval duration. Keywords:Fatigue, Elbow, Muscles, Torque, Rest interval
Background Muscle fatigue has been received attention in the literature. There is a consensus that defines it as the inability of muscles to produce force (torque) with the same efficiency over a period of time or after repeated contractions [1]. Although this matter has been investigated several times in the scientific community, there is the need to understand some processes that are relevant to this mechanism. Recent studies [13] measured muscle fatigue based on new technologies and also based on the development of the isokinetic dynamometer. The dynamometer is able to measure the muscle torque in particular joints and it also limits the speed and range of motion [4]. It was showed that the torque produced in the joint decreases after mul tiple repetitions of the same movement. This fact characterizes the muscle fatigue [4]. The protocols performed to measure muscle fatigue through the isokinetic dynamo metry consider the speed, amplitude, time of execution of the movement and the rest interval between sets [1,2,5,6]. These protocols have used a single rest interval duration for the movements of flexion and extension. However, it is not clear in the literature the involvement of this equipment in the elbow flexor muscle group. Therefore, we aimed to investigate the effect of different rest intervals duration on fatigue in the elbow flexor muscle group.